DESCRIPTION: (Applicant's Description) A monoclonal antibody core facility was created at the inception of this program project to produce reagents necessary for advancement of much of the research of the program. Monoclonal antibodies are fundamental to the cellular and molecular biologic approaches which the program scientists routinely use. It was recognized at the beginning of the program that these reagents were essential to the program?s success, that the commercial production of the various antibodies needed was excessively costly, that their production in individual labs posed an avoidable burden for everyone involved, and that a central facility staffed by experts and dedicated to the program could, in principle, generate the most valuable antibodies in a timely and cost-effective manner. The monoclonal antibody core has successfully produced monoclonal antibodies for every member of the program.